煤与生物质共热解工艺的研究进展

热解是将固态原料转化为液体燃料、可燃气和焦的重要途径,是实现生物质资源清洁、高效利用的重要技术。将生物质与煤混合共热解是生物质资源利用的重要方法,两者混合热解不仅有助于降低CO_2的排放量,还能有效地解决能源短缺和环境污染带来的问题。文章综述了煤与生物质共热解技术的研究进展,系统地介绍了共热解过程中煤与生物质的相互作用以及热解温度、混合比例、滞留时间、升温速率、矿物质成分、物料粒径和热解反应器类型等因素对热解过程的影响,并对煤与生物质共热解技术的发展前景进行了展望。     

生物质热解的典型影响因素及技术研究进展

生物质通过热解可以获得热解气、生物油以及生物炭,实现其资源化、清洁高效利用。文章阐述了生物质热解过程中的反应机理,探讨了不同热解条件(如温度、升温速率和热解气氛)以及不同预处理方式(如烘焙、干燥、酸洗和水热)对生物质热解特性的影响。基于催化剂特性差异将用于生物质热解的催化剂分为固体酸和碱基催化剂并进行概述。在总结前人研究进展的基础上,梳理了有热载体和无热载体的生物质热解反应器的发展进程,针对生物质热解的研究因素较为单一的现状,提出通过围绕"微观结构-宏观调控"开展多尺度、定向调控、高效制备热解产物的方法,并对热解过程中自由基的变化研究不足以及热解催化剂失活等问题提出了展望,从而为生物质热解技术的发展提供理论依据,加快实现我国生物质的资源化利用。     

生物质热解燃料的生产

利用热解及其相关技术可将生物质转化成焦炭、生物油和合成气。本文重点介绍了生物质热解技术的研究概况,简介了利用生物质热解生产燃料的优点。指出：利用湖泊等自然水体中的浮游藻类做热解材料,在解决水体环境污染方面具有很好的社会效益和经济效益。     

木质素基本结构、热解机理及特性研究进展

木质素是由三种苯基丙烷单元通过醚键和C—C键相互偶联形成的复杂高分子聚合物,并且与碳水化合物交联形成复杂的结构,其在自然界中的储量仅次于纤维素,传统木质素利用方式效率低,资源浪费严重。热解是一种重要的木质素高效转化利用技术,木质素复杂的结构特性会显著影响其热解过程和产物分布。本文综述了木质素结构和热解机理,概述了不同原料和不同提取方式木质素的热解特性,最后对木质素热解转化进行了展望,为木质素的资源化利用提供理论基础。     

生物质能的应用前景分析

生物质能是可再生能源的重要组成部分，生物质能的高效利用，对解决能源和生态环境问题将起到十分积极的作用。概述了目前生物质能的主要转换方式。化学转变中的液化、气化和热解技术是目前主要研究方向。通过液化、热解可以直接得到一些化工产品；通过气化可以得到合成气，可以用来合成氨或者甲醇。总之，通过这些转变不但可以得到一些化工产品，而且可以缓解化石能源桔竭带来的能源危机。     

我国煤热解多联产技术的发展概况

目前煤热解多联产已成为一项提高煤炭资源综合利用率的高新技术,是未来洁净煤主要的发展方向.以煤热解为核心的多联产工艺已成为我国煤炭利用的主要途径,通过煤热解多联产技术可有效地将煤炭化工和电力工业结合起来,不仅解决了煤炭利用率低下、化工产品制造成本高等问题,而且对我国的环境保护有着重要影响.介绍了国内外煤热解多联产工艺的研究状况,并对国内几种典型的煤热解多联产工艺进行了评述,总结了当前煤热解多联产工艺的优缺点和主要发展方向.     

玉米芯产糠醛残渣的热解利用分析

在极低水固比的稀硫酸/甲苯体系（简称ELW体系）中,玉米芯半纤维素可快速高产糠醛。为了构建经济高效的生物炼制体系,玉米芯ELW残渣的利用亟待研究。以真实糠醛厂渣为对照,本文综合比较了ELW渣和糠醛厂渣作为固体燃料进行热解（常规热解和快速热解）并高值化利用的潜力。研究发现,ELW渣和糠醛厂渣均有一定的碳化;ELW渣的常规热解产物与糠醛厂渣类似;而其快速热解的左旋葡聚糖产率明显优于玉米芯和糠醛厂渣。     

块状废轮胎固定床热解特性实验研究

国内外对于废旧轮胎热解的研究大多集中在对轮胎小颗粒的探索上,对于破碎成本较低的大块状轮胎的热解较少有人涉及.为了探究块状轮胎的热解特性,文章在外热式固定床热解炉上进行了不同热解温度下块状废轮胎热解特性的实验研究.结果表明:块状废轮胎热解产生的燃气成分主要为CH4,H2以及大分子烃类CnHm,且其燃气产率随热解温度的升高而增加.当热解温度高于550℃时,热解产物CnHm有二次裂解现象,热解产生的燃气具有较高热值;热解温度为600℃时,燃气热值可以达到26 MJ/m3;随着热解温度的提高,热解炭中挥发分含量减少,固定碳含量略有增加,热解温度对热解油及热解气产率影响明显.与小颗粒轮胎相比,块状轮胎热解气中小分子气体CH4,H2等含量相对较少,而大分子烃类含量相对较多.热解产物产率方面,热解炭和热解气的产率更大,焦油产率降低.     

大豆秆的FTIR分析及热解机理研究

为高效利用大豆秆,有效控制热解产物,采用FTIR分析了大豆秆的组分,利用热重法在4个不同升温速率下对大豆秆的热解行为进行了研究。结果表明,大豆秆主要组分为纤维素、半纤维素、木质素和木聚糖等。大豆秆热解可分为4个阶段,随着升温速率的提高,主反应区热重曲线和微分热重曲线都向高温方向移动,热解最大速率以及相对应的温度随之提高;Ozawa法计算大豆秆主热解区间的活化能值集中在98.78～191.75kJ/mol;譒atava机理函数推断法得出大豆秆热解的最可能机理属于19号机理函数Avrami-Erofeev方程,随机成核和随后生长,反应级数n=3。     

山东科大生物质热解生产燃料油技术取得重大突破

山东科技大学生物质热解生产燃料油技术取得重大突破,可成功地以木屑、秸秆、稻壳为原料生产液体燃料油从而为新能源利用开辟了一条路,将木屑、秸秆、稻壳等进行快速热解生产液体燃料油,木屑产油率可达65％以上.     

生物质热解液化技术研究现状

对生物质热解液化技术及其液化机理进行阐述,并介绍国内外生物质热解反应器类型及其发展现状,分析热解过程中的影响因素。生物质热解液化技术很大程度上能缓解当今社会的能源危机和环境污染,是人类开发可再生资源的一种有效途径。     

Waste pyrolysis and generation of storable char

Sustainable cities require the generation of energy from waste that cannot be economically reused or recycled. This study focuses on slow pyrolysis that can generate a high yield of char along with liquid and gas products from waste. Char is high in energy content, storable and transportable with low cost so that it can be used as an intermediate medium for high efficiency energy conversion. Pre‐processed municipal waste pellets, wood and grass were pyrolysed in a batch type reactor for a final temperature ranging from 350 to 700°C, and the char products were characterized. The mass yields of char ranged from 55 to 20% for the tested temperature range, recovering 70–30% of energy and 62–30% of carbon in the raw material. The gross calorific value of char was 30–35 MJ kg^?1 on a dry ash free basis. The ash content of raw materials was a key parameter for the quality of char, since its proportion increased by 2–4 times in char depending on the mass yield. A significant amount of volatile metals such as Hg, As and Pb in the waste sample was evaporated at 500°C. Therefore, evaporation of volatile metals was another important parameter in determining the pyrolysis temperature and fuel residence time. The char did not show significant morphological change in the tested range of temperatures. It was concluded that slow pyrolysis of waste for char production should be performed below 500°C in order to increase the energy yield and also to reduce the evaporation of heavy metals. Copyright © 2006 John Wiley & Sons, Ltd.     

生物质快速热解制取生物油

生物质能源是可再生能源的重要组成部分,具有资源丰富和低污染的特点,它的开发与利用已成为21世纪研究的重要课题。本文概述了生物质快速热解的过程、设备及其产物,并对热解的重要产物——生物油的组成、性质、精制以及转化利用进行了详细的阐述。     

Pyrolytic liquid fuel: A source of renewable electricity generation in Makkah

Millions of Muslims from all over the world visit the Holy Cities of Saudi Arabia: Makkah and Madinah every year to worship in form of Pilgrimage (Hajj) and Umrah. The rapid growth in local population, urbanization, and living standards in Makkah city along with continually increasing number of visitors result in huge municipal solid waste generation every year. Most of this waste is disposed to landfills or dumpsites without material or energy recovery, thus posing substantial environmental and health risks. The municipal plastic waste is the second largest waste stream (up to 23% of total municipal waste) that is comprised of plastic bottles, water cups, food plates, and shopping bags. The sustainable disposal of plastic waste is challenging task due to its clogging effects, very slow biodegradation rates, and presence of toxic additives and dyes. Pyrolysis is one of the promising waste-to-energy technology for converting municipal plastic waste into energy (liquid fuel) and value-added products like char. The produced liquid fuel has the potential to be used in several energy-related applications such as electricity generation, transportation fuel, and heating purposes. It has been estimated that the plastic waste in Makkah city in 2016 can produce around 87.91 MW of electricity. This is projected to increase up to around 172.80 MW of electricity by 2040. A global warming potential of 199.7 thousand Mt.CO₂ eq. will be achieved with savings of 7.9 thousand tons emission of CH₄, if pyrolysis technology is developed in Makkah city. Furthermore, a total savings of 297.52 million SAR from landfill diversion, electricity generation, and carbon credits would be possible to achieve in 2016 from pyrolysis. These economic benefits will increase every year and will reach up to 584.83 million SAR in 2040.     

CO2-free hydrogen production via microwave-driven methane pyrolysis

Hydrogen will play an integral role in achieving net-zero emissions by 2050. Many studies have been focusing on green hydrogen, but this method is highly electricity intensive. Alternatively, methane pyrolysis can produce hydrogen without direct CO₂ emissions and with modest electricity inputs, serving as a bridge from fossil fuels to renewable energies. Microwaves are an efficient method of adding the required energy for this endothermic reaction. This study introduces a new method of CO₂-free hydrogen production via non-plasma methane pyrolysis using microwaves and carbon products of this process. Carbon particles in the fluidized bed absorb microwave energy and create a hot medium (>1200 °C) in contact with flowing methane. As a result, methane decomposes into hydrogen and solid carbon achieving over 90% hydrogen selectivity with ∼500 cumulative hours of experiments This modular pyrolysis system can be built anywhere with access to natural gas and electricity, enabling distributed hydrogen production.     

污水污泥热解过程的能量平衡与反应热分析

依据能量守恒定律,通过分析污水污泥热解过程的能量利用、耗散和回收情况,提出了污泥热解制取三相产物处理系统的能量平衡模型,分析计算了污泥热解反应热,并利用回收率和耗能比对热解处理系统的耗能状况进行了评价.结果表明:能量利用过程中总存在能源的耗散,减少能耗的主要方式是尽可能提高产物的能值、降低热消耗和废弃的能量;在不同的热解工况下,热量损失的差别明显,热解停留时间长、升温速率慢、热解温度高均会导致输入能量和热损失增大;能耗评价也验证了热解技术能够回收更多的能量,可以获得更大的能耗比.     

升温速率对废塑料热解过程的影响

选取废旧塑料聚乙烯（polyethylene,PE）、聚丙烯（polypropylene,PP）、聚氯乙烯（polyvi-nyl chloride,PVC）及其混合物,在氮气气氛下进行热解实验,实验温度从室温到700℃,升温速率分别为10℃/m in、20℃/m in和30℃/m in。讨论了不同升温速率对废塑料热解过程的影响,并采用Coast-Redfern法进行了热解动力学分析,得到了三种废塑料及其混合物的热解特性及反应动力学参数。研究结果表明,升温速率对热解速率,热解温度段,活化能,频率因子都有影响。升温速率越快,热解反应越快,所需的活化能也越大,热解过程对能量的消耗越多。因此,在废塑料热解过程中,要综合考虑升温速率,热解原料,热解温度等条件。本文可为废塑料热解工艺的研究提供理论依据和参考数据。     

Conversion of waste tires to liquid products via sodium carbonate catalytic pyrolysis

This study deals with the pyrolysis of waste tires supplied from the transport industry. The base material of tire is latex, which is derived from natural rubber trees. Nowadays rubber (Hevea brasiliensis) is a fast-growing tropical tree crop, which is being cultivated for latex and ultimately for tire production. Waste tires can be recycled for energy and valuable materials in many ways; however tire burning is the most common practice for heat generation. In recent years, the catalytic conversion of waste tires through pyrolysis into liquid, solid, and gas products was investigated. Liquids product was produced from the catalytic pyrolysis of waste tire at high temperature (up to 600°C) using sodium carbonate (Na₂CO₃) as a catalyst. Thermo-physical characteristics of the produced liquid samples showed that up to 85% of the produced oil can be used in internal combustion engines. Gasoline and diesel fuel contents in the liquid products are 45% and 40%, respectively. The gas chromatographic (GC) analysis of the volatile fraction of pyrolysis products showed styrene (28.1%) and butadiene (10.7%) as dominant compounds. The gaseous phase includes C₁–C₄ hydrocarbons (4.8%) and the liquid phase includes C₅–C₈ hydrocarbons (6.5%) of the total products.     

生物质液化技术面临的挑战与技术选择

生物质液化技术可将低品位的固体生物质完全转化成高品位的液体燃料或化学品,是生物质能高效利用的主要方式之一。按照机理,液化技术可以分为热化学法、生化法、酯化法和化学合成法(间接液化),热化学法液化又分为快速热解技术和高压液化(直接液化)技术。生物质热化学法液化已成为国内外生物质液化的研究开发重点和热点,快速热解液化技术和高压液化技术是最具产业化前景的生物质能技术,生化法液化技术也是生物质能的研究热点。化学合成法液化技术并不适用于生物质液化,而利用生物柴油进一步生产生物航空煤油是得不偿失的,不仅成本高、资源利用率低,而且全生命周期碳排放增加,还不符合未来生物航煤的发展趋势。生物质含水量的高低是影响生物质液化过程中能耗、效率、污染指数和经济性指标等的关键因素,应根据含水量合理选择生物质液化技术。快速热解液化技术适用于低含水农林废弃物,高压液化和生化法液化技术适用于高含水生物质,酯化法液化技术适用于不可食用油脂,而各种液化技术均不适用于城市生活垃圾的处理,建议将其用作燃气型气化原料。